Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751625Ab0KSIWc (ORCPT ); Fri, 19 Nov 2010 03:22:32 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:47489 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920Ab0KSIWb (ORCPT ); Fri, 19 Nov 2010 03:22:31 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 19 Nov 2010 17:16:53 +0900 From: KAMEZAWA Hiroyuki To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , minchan.kim@gmail.com, Bob Liu , fujita.tomonori@lab.ntt.co.jp, m.nazarewicz@samsung.com, pawel@osciak.com, andi.kleen@intel.com, felipe.contreras@gmail.com, "akpm@linux-foundation.org" , "kosaki.motohiro@jp.fujitsu.com" Subject: [PATCH 4/4] alloc_contig_pages() use better allocation function for migration Message-Id: <20101119171653.3c476064.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20101119171033.a8d9dc8f.kamezawa.hiroyu@jp.fujitsu.com> References: <20101119171033.a8d9dc8f.kamezawa.hiroyu@jp.fujitsu.com> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4671 Lines: 123 From: KAMEZAWA Hiroyuki Old story. Because we cannot assume which memory section will be offlined next, hotremove_migrate_alloc() just uses alloc_page(). i.e. make no decision where the page should be migrate into. Considering memory hotplug's nature, the next memory section near to a section which is being removed will be removed in the next. So, migrate pages to the same node of original page doesn't make sense in many case, it just increases load. Migration destination page is allocated from the node where offlining script runs. Now, contiguous-alloc uses do_migrate_range(). In this case, migration destination node should be the same node of migration source page. This patch modifies hotremove_migrate_alloc() and pass "nid" to it. Memory hotremove will pass -1. So, if the page will be moved to the node where offlining script runs....no behavior changes. Signed-off-by: KAMEZAWA Hiroyuki --- include/linux/page-isolation.h | 3 ++- mm/memory_hotplug.c | 2 +- mm/page_isolation.c | 21 ++++++++++++++++----- 3 files changed, 19 insertions(+), 7 deletions(-) Index: mmotm-1117/include/linux/page-isolation.h =================================================================== --- mmotm-1117.orig/include/linux/page-isolation.h +++ mmotm-1117/include/linux/page-isolation.h @@ -41,7 +41,8 @@ extern void alloc_contig_freed_pages(uns int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn); unsigned long scan_lru_pages(unsigned long start, unsigned long end); -int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn); +int do_migrate_range(unsigned long start_pfn, + unsigned long end_pfn, int node); /* * For large alloc. Index: mmotm-1117/mm/memory_hotplug.c =================================================================== --- mmotm-1117.orig/mm/memory_hotplug.c +++ mmotm-1117/mm/memory_hotplug.c @@ -724,7 +724,7 @@ repeat: pfn = scan_lru_pages(start_pfn, end_pfn); if (pfn) { /* We have page on LRU */ - ret = do_migrate_range(pfn, end_pfn); + ret = do_migrate_range(pfn, end_pfn, numa_node_id()); if (!ret) { drain = 1; goto repeat; Index: mmotm-1117/mm/page_isolation.c =================================================================== --- mmotm-1117.orig/mm/page_isolation.c +++ mmotm-1117/mm/page_isolation.c @@ -193,12 +193,21 @@ unsigned long scan_lru_pages(unsigned lo struct page * hotremove_migrate_alloc(struct page *page, unsigned long private, int **x) { - /* This should be improooooved!! */ - return alloc_page(GFP_HIGHUSER_MOVABLE); + return alloc_pages_node(private, GFP_HIGHUSER_MOVABLE, 0); } +/* + * Migrate pages in the range to somewhere. Migration target page is allocated + * by hotremove_migrate_alloc(). If on_node is specicied, new page will be + * selected from nearby nodes. At hotremove, this "allocate from near node" + * can be harmful because we may remove other pages in the node for removing + * more pages in node. contiguous_alloc() uses on_node=true for avoiding + * unnecessary migration to far node. + */ + #define NR_OFFLINE_AT_ONCE_PAGES (256) -int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) +int do_migrate_range(unsigned long start_pfn, unsigned long end_pfn, + int node) { unsigned long pfn; struct page *page; @@ -245,7 +254,7 @@ int do_migrate_range(unsigned long start goto out; } /* this function returns # of failed pages */ - ret = migrate_pages(&source, hotremove_migrate_alloc, 0, 1); + ret = migrate_pages(&source, hotremove_migrate_alloc, node, 1); if (ret) putback_lru_pages(&source); } @@ -463,6 +472,7 @@ struct page *__alloc_contig_pages(unsign struct zonelist *zonelist; enum zone_type highzone_idx = gfp_zone(gfpflag); unsigned long zone_start, zone_end, rs, re, pos; + int target_node; if (node == -1) node = numa_node_id(); @@ -516,6 +526,7 @@ retry: if (!zone) return NULL; + target_node = zone->zone_pgdat->node_id; zone_start = ALIGN(zone->zone_start_pfn, 1 << align_order); zone_end = zone->zone_start_pfn + zone->spanned_pages; @@ -548,7 +559,7 @@ next_zone: for (rs = scan_lru_pages(rs, re); rs && rs < re; rs = scan_lru_pages(rs, re)) { - int rc = do_migrate_range(rs, re); + int rc = do_migrate_range(rs, re, target_node); if (!rc) migration_failed = 0; else { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/